1. For eel, a 10 p.m. specimen : EXAMPLE2. Ambassador Simon is on one : MISSION3. A leader no matter how you look at it : AGA4. She sounds like a ringer : NELL5. Open up can : UNCAP6. Concern of my C.E.O., no? : ECONOMY7. Ellen Reed is drawing a lot of interest : LENDER8. Bees are likely to get drunk on them : BEERS9. U.S.S.R. native : RUSS10. Official's fake first name? : ART11. Goalie's stain : SOILAGE12. Old lover who used no prose : SPOONER13. Carried away, pet ran : ENRAPT15. Tees off on ranges : ANGERS17. Every other position in guest list. Understand? : GETIT22. It's a man of endurance : STAMINA24. Can 507 paintings be his? : DAVINCI26. It ranks as a Carroll creature : SNARK28. A thousand leaving the pampas with them : PAPAS30. One familiar with salary cap : CPA32. Murray may go to play : RUR35. Snakes that can't multiply? : ADDERS36. Not one of our top 500 students : DROPOUT37. Rib mama about instrument : MARIMBA38. Flat piece of paper : LEASE39. Geological area for a renter : TERRANE40. Where a prison escapee hides out : CONCAVE41. Furious grandee : ENRAGED42. He plants cedar, it is said : SEEDER45. Named idle tease : TITLED48. It's cruel and filthy : LUCRE49. Follows musical signs : SINGS52. Short course for a Cole : ANAT53. Kind of culture : AGRI56. Natl. rap month : APR57. Old land where Jaguar ended up? : UAR

Answer summary: 1 unique to this puzzle, 1 unique to Shortz Era but used previously.